That "three point jam" you described is exactly what my LWD 10mm barrel is doing! And a slap on the mag usually chambers the round. Ive hesitated sending it in because Im afraid they'll ruin chamber support.

On the other hand, my LWD 10mm - .40sw conversion barrel has been perfect! The case support isnt really there, but thats never bothered me at all since the only round I ever intend to push very hard is the 10mm...